If the Edmonton police make good on their original media release - we may very well see the upstanding citizen prosecuted for that very offence.
The worst possible outcome is for the courts to establish precedence and for that decision to spread throughout the rest of the country.
Hey, if we ever run into a situation even remotely like what's going on in NY I will definitely be concerned. However, I'm just not convinced that is going to happen up here.
Look at the case discussed earlier, for example. Puddy was in the front of the crowd at the G-20 protests sporting a mohawk, dressed all in black (similar in style to the "Black Block", potentially violent protesters) with a t-shirt with the words "Police Bastards" on it and was carrying a knife which met the legal definition of a prohibited weapon.
And yet, the judge found he was simply a hard working, respectful guy and found him not guilty of a prohibited weapons charge even though the knife met that legal definition.
Back to the Edmonton case specifically, the Edmonton Journal article mentions the police intend to use section 88 as the primary basis for their crackdown. In reading this section, it doesn't say it is illegal to carry or possess a weapon. Rather, it's illegal to carry or possess a weapon "for a purpose dangerous to the public peace or for the purpose of committing an offence" (section 91 is the one which makes simple possession illegal, but that only applies to prohibited weapons). The Crown will need to prove that the individual charged is in possession of the weapon for one of these reasons.
A more likely scenario that could impact otherwise law-abiding people was mentioned in that article though; the possibility of amending the Alberta Liquor and Gaming Act to prohibit carrying knives into bars and nightclubs.
This is actually similar to the what the Calgary city council did a little while ago when it enacted its
Public Behavior bylaw. It's now a bylaw infraction if you "carry a visible knife in any public place." If I recall correctly, this aspect of the bylaw came from the fact that there was nothing illegal about panhandlers having hunting knives on their belts which was intimidating some people (the whole bylaw seems largely targeted at controlling the behaviour of the homeless and other non-business type people downtown).
That said, its unlikely this bylaw is going to be widely enforces so those outside of the "targeted" groups likely have little to fear.